Published June 5, 2019 © GPL3+

Bluetooth Controlled Bot (Using Adafruit L293D Motor Driver)

A robot which is controlled by an HC-05 module and receives commands using a Bluetooth terminal app.

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Bluetooth Controlled Bot (Using Adafruit L293D Motor Driver)

Things used in this project

Hardware components

Arduino UNO

Adafruit L 293 D motor driver

HC-05 Bluetooth Module

Jumper wires (generic)

Breadboard (generic)

DC motor (generic)

Software apps and online services

Arduino IDE

Bluetooth Terminal

Hand tools and fabrication machines

Multitool, Screwdriver

Wire Stripper & Cutter, 18-10 AWG / 0.75-4mm² Capacity Wires

Story

The idea was to make an extremely simple Bluetooth-controlled robot. It was done with an effort to understand the working of the Bluetooth module (HC-05) and how to use it. It can move forward, backward, left, right and stop by giving letter inputs of 'f', 'b', 'l', 'r' and 's' respectively.

Note: This model uses Adafruit L293D motor shield. This requires you to download and use a particular library for the same. You can use a generic motor shield as well but the code will change. For those of you who want to use the Adafruit one, please refer the following link:

(All the credit goes to the creator of the video, I learnt how to use the motor shield from the above mentioned link and hence I am merely recommending the same)

The other prerequisite needed is how to use the bluetooth module which can be learnt easily online.

Top View

Close up shot

Code implemented for the bot

char j;
String iS="";
#include<AFMotor.h>//Follow instructions in the video to understand how to import the same(All credit on how to use the same goes to the creator of the video)
AF_DCMotor motor1(1);
AF_DCMotor motor2(2);
void setup()    
{
 motor1.setSpeed(200);//Can be set from 0-255
 motor2.setSpeed(200);//Can be set from 0-255
 Serial.begin(9600);           
}
void loop()
{
  if(Serial.available()){
  while(Serial.available())
    {
      char iC = (char)Serial.read();
      iS += iC;       
    }
    Serial.println(i);
    while (Serial.available() > 0)  
    { j = Serial.read() ; }      
    if(iS == "f"){  //To move forward      
      motor1.run(FORWARD);
      motor2.run(FORWARD);
    }else if(iS == "b"){ //To move backward 
      motor1.run(BACKWARD);
      motor2.run(BACKWARD);
    }
    else if(iS == "l"){  //To move left
      motor1.run(FORWARD);
      motor2.run(RELEASE);
    }
    else if(iS == "r"){//To move right 
      motor1.run(RELEASE);
      motor2.run(FORWARD);
    }
    else if(iS == "s"){  //To stop
      motor1.run(RELEASE);
      motor2.run(RELEASE);
    }
    iS = "";
  }
}